There are occasions when only one political party can develop a particular theory successfully. These are when that theory runs counter to the party’s traditional line. This is not hard to explain: when a theory’s fiercest detractors belong to a party that suddenly adopts it, self-doubt, combined with party loyalty, mutes their criticism. As David Cameron sets out to win people over to the notion of the Big Society, he will sense behind him the Conservative creed that built up around Lady Thatcher’s most famous quotation: “They are casting their problems on society and who is society? There is no such thing! There are individual men and women, and there are families, and no government can do anything except through people, and people look to themselves first.” Although this is often quoted out of context, it is clear that Mr Cameron is departing from the appeal to self-interest (enlightened or otherwise) that drove Conservatism in the 1980s and ’90s.

But as the Prime Minister moves into uncharted territory — uncharted, that is, apart from Communitarianism, the stakeholder programme, perhaps even Socialism — he is still enough of a Conservative to know that his Big Society ideal will be made or broken by one thing: money.